Mounting member for printing plate and apparatus of making same

ABSTRACT

A mounting member for a printing plate and a method of making same are provided. The mounting member is made of a plastic sheet material which is solvent resistant, strong, dimensionally stable, conforms truly to the printing plate cylinder, and is of uniform thickness. A leading edge of the mounting member is turned back to form a structurally integral lip thereon which is readily connected to a flange on a printing plate cylinder. The integral lip is inexpensive to produce, requires no separate parts, and cannot loosen or pull off of the mounting member. The mounting member can be readily made by means of a table-top, heated, bending and forming apparatus through which the mounting member can be moved to bend and form the lip quickly and inexpensively.

United States Patent [191 Saunders et al.

[ 1 July 29, 1975 [75]v Inventors: Philip G. Saunders; Neil M.

Waterbury, both of Toledo, Ohio [73] Assignee: Container GraphicsCorporation,

Toledo, Ohio [22] Filed: Apr. 19, 1974 [21] Appl. No.: 462,225

Related U.S. Application Data [62] Division of Ser. No. 345,573, March28, 1973,

1,909,930 5/1933 Ridder 72/166 2,014,150 9/1935 Stenersen.. 425/392 X3,001,569 9/1961 Gradt 72/176 3,339,005 8/1967 Brown et al. 425/384 X3,509,599 5/1970 Driza et al. 425/393 X Primary ExaminerRobert L.Spicer, Jr. Attorney, Agent, or Firm-Allen D. Gutchess, Jr.

[57] ABSTRACT A mounting member for a printing plate and a method ofmaking same are provided. The mounting member is made of a plastic sheetmaterial which is solvent resistant, strong, dimensionally stable,conforms truly to the printing plate cylinder, and is of uniformthickness. A leading edge of the mounting member is turned back to forma structurally integral lip thereon which is readily connected to aflange on a printing plate cylinder. The integral lip is inexpensive toproduce, requires no separate parts, and cannot loosen or pull off ofthe mounting member. The mounting member can be readily made by means ofa table-top, heated, bending and forming apparatus through which themounting member can be moved to bend and form the lip quickly andinexpensively.

4 Claims, 12 Drawing Figures PATENTEnJuLes I975 SHEET MOUNTING MEMBERFOR PRINTING'PLATE AND APPARATUS MAKING SAME This a division, ofapplication Ser. No. 345,573 filed Mar. 28, 1973, now abandoned.

This invention relates to a mounting member for printing plates and to amethod for making same.

Mounting sheets for printing plates, heretofore have been made ofrubber-impregnated clothor paperplastic laminates. In order to producemounting lips on such mounting sheets, separate elongate lip members hadto be stapled or sewn to edges of the sheets. Such a lip member requiredseparate parts which had to be inventoried, stored, etc. The elongatelip members also had to be cut to particular lengths in many instances.and required the additional step of stapling or otherwise affixing themto the mounting sheets. Such lip members also had a tendency to workloose from time to time during the printing operation, requiring a shutdown. I

The present invention provides a printing plate mounting member made ofa plastic sheet material which is solvent resistant, strong,dimensionally stable, conforms truly to the plate cylinder, and is ofuniform thickness. A mounting lip is provided on the leading edge of themounting member which is structurally integral therewith. The lip isformed by sequentially heating the leading edge of the mounting member,sequentially bending it up and back on itself, and sequentially holdingthe bent portion while sequentially cooling the leading edge portion andlip to establish a permanent lipfThe structurally-integral lip is low incost to produce and is strong, not tending to pull away or loosen asseparate lips heretofore employed. The integral lip also eliminatesextra parts and extra labor required to cut separate lip members toproper length and affix them to the mounting sheet.

It is, therefore, a principal object of the invention to provide animproved mounting member for a'rubber printing plate. 1

Another object of the invention is to provide a mounting member forprinting plates having a structurally-integral lip formed thereon.

A further object of the invention is to provide a method of making aprinting plate mounting member with a structurally-integral lip thereon.

Still another object of the invention is to provide a printing platemounting member which is dimensionally stable, of uniform thickness, andstrong.

Other objects and advantages of the invention will be apparent from thefollowing detailed description of a preferred embodiment thereof,reference being made to the accompanying drawings, in which:

FIG. 1 is a view in perspective of a printing plate cylinder having amounting member according to the invention fastened thereto and aprinting plate affixed to the mounting member;

FIG. 2 is an enlarged fragmentary view in perspective of the mountingmember of FIG. 1;

FIGS. 35 are detailed, sectional views taken along the lines 3-3, 44,and 5-5 of FIG. 1;

FIG. 6 is a fragmentary plan view of forming apparatus for producing themounting member of FIGS. 1-5;

FIG. 7 is a view in elevation of the apparatus of FIG. 6; and

FIGS. 8-12 are enlarged, detailed views in transverse cross sectiontaken along the lines 8-8, 9-9, 10-10, 11-11, and 12-12 of FIG. 6.

Referring to the drawings, and particularly to FIG. 1, a printing platecylinder 20 has a mounting member or sheet 22 fastened thereto, with arubber printing plate 24 mounted thereon. The assembly is used in arotary printing press to print indicia on sheet material such ascorrugated board which is directed between the printing plate cylinder20 and another roll located thereunder (not shown). Typically, thecylinder 20 has a longitudinally-extending channel or groove 26 (FIG. 3)with a first mounting flange 28' affixed to the cylinder 20 in a flushmanner with the flange extending ov'er a portion of the channel 26. 'Asecond flange 30 is also affixed to the cylinder 20 in a flush mannerand extends over another portion of the channel 26 toward the firstflange 28.

Referring particularly to FIG. 2, the mounting member 22 comprises asingle sheet 32 of plastic material of predetermined size and shape. Theplastic material can be a general purpose, calendered, rigid polyvinylchloride sheeting which is commercially available. The material can beobtained for example, from Tenneco Chemicals, Inc. under the designationV.C.H. 8001. Typically, the sheet is 0.030 inch thick with a variationof only i 0.001 inch. However, the sheet also is available in athickness of 0.050 inch which is suitable for the invention, with athickness range of 0.020 0.070 inch being generally satisfactory. Thesheet 32 has a front, convex surface 34 and a back, concave surface 36and either can be formed with a fixed curve or can assume the curve ofthe cylinder 20 when mounted thereon.

A leading edge portion 38 of the sheet has a structurally-integral lipor flange 40 connected thereto by an intermediate, arcuate web 42. Thelip 40 is generally parallel to the sheet 32 and is spaced therefrom bythe web 42 a distance substantially equal to the thickness of the firstflange 28. Along a trailing edge portion 44 of the mounting member 22,spaced means are provided for fastening resilient connecting means tomount the member 22 on the cylinder 20. These means in this instance areshown in the form of openings 46. The sheet 32 is sufficiently strongthat the openings 46 can be employed without the necessity of usinggrommets therewith, as has been the case with mounting sheets heretoforeknown.

The printing plate 24 can be of molded rubber with suitable indiciaindicated at 48 formed thereon. As shown in FIG. 5, the printing plate24 can be mounted on the front surface 34 of the mounting member 22 bymeans of adhesive 50 or other suitable means.

Tension bands 52 constitute resilient connectors for affixing themounting member 22 and the printing plate 24 on the cylinder 20. Thetension bands 52 include resilient straps 54 to which first, narrowhooks 56 (FIG. 4) are suitably bonded or otherwise affixed, with thehooks received in the openings 46 in the mounting sheet 32. The tensionbands also include broader metal hooks 58 (FIG. 3) at the opposite endswhich are placed over the second flange 30 of the cylinder 20. The bands52 are in tension and place the mounting member 22 in tension, with theleading edge lip 40 received on the first flange 28.

Referring more particularly to FIGS. 6 and 7, apparatus for forming themounting member 22 is indicated at 60. Basically, the apparatus includesa non-metallic supporting base 62 and a metal edge portion 64 in whichheating, bending, and cooling take place. The

edge portion 64 generally includes a first entry zone 66, a preheatingand initial forming zone 68, a further heating and forming zone 70, anda cooling zone 72.

The sheet 32 is first positioned on the base 62 with the concave surface36 up and with the edge of the leading edge portion 38 abutting ashoulder stop 74 in the first zone. The leading edge portion 38 of thesheet extends under a hold-down bar 76 which extends along the entireedge portion 64 and is adjustably positioned above the supporting base62 by supporting brackets 78 having adjusting screws 80 (FIG. 12) whichcan move the hold-down bar 76 up and down slightly relative to the base62. In the entry zone 66, the sheet 32 essentially is just aligned withthe metal portion 64. In the initial heating and forming zone 68, thesheet is initially heated to some extent by an electric heating element82 which extends into both of the heating zones 68 and 70. Temperaturein the zones is controlled by a thermostat 84 connected in series withthe heating element 82 and connected through a master switch 86 (FIG. 7)to a power source 88. In the first heating and forming zone 68, the edgeportion 38 of the sheet is bent to a generally vertical position by aheated forming block 90, as shown in FIGS. 8 and 9, heat beingtransferred through the forming block 90 from the element 82 to thesheet.

In the heating and forming zone 70, the sheet is further heated by theelement 82 and is bent back on itself by an overhead forming block 92,as shown in FIGS. and 11. With this arrangement, the lip 40 and the web42 assume the position as shown in FIGS. 2 and 3 by the time the sheet32 reaches the end of the zone 70.

The heating zone 70 and the cooling zone 72 are separated by aninsulating block 94, as shown in FIG. 7, with the cooling zone 72 thenbeing approximately at ambient temperature. The cooling zone 72 includesa main metal block 96 and a hold-down block 98 which maintain the sheet32 in the desired position until the sheet is sufficiently cooled toretain the shape of the lip 40 and the web 42. As the sheet is movedsequentially out of the cooling zone 72, the lip is completed and isready to be used as the mounting plate 22 for the printing plate 24.With the mounting member 22 and the printing plate 24 assembledtogether, the mounting member 22 is mounted on the cylinder 20 with theaid of the tensioning bands 52 to render the cylinder 20 ready foroperation.

Various modifications of the above-described embodiments of theinvention will be apparent to those skilled in the art and it is to beunderstood that such modifications can be made without departing fromthe scope of the invention, if they are within the spirit and the tenorof the accompanying claims.

We claim:

1. Apparatus for making a mounting sheet for mounting a printing plateon a printing cylinder. said mounting sheet having astructurally-integral lip, said apparatus comprising means forsupporting a heat-softenable plastic sheet of a given size and shape andhaving at least one straight edge, an entry zone having means forreceiving and positioning the edge of the sheet. at least one heatingand forming zone having means for heating the edge of the sheet and forbending the edge upwardly away from the plane of the sheet andrearwardly in a direction substantially parallel to the plane of thesheet to form the structurally-integral lip, and a cooling zone havingmeans for cooling the bent edge of the sheet while maintaining the bentedge in its bent positiO'Il.

2. Apparatus according to claim 1 characterized by means for insulatingsaid heating means from said cooling means.

3. Apparatus according to claim 1 characterized by a hold-down barextending substantially the length of said heating means and saidcooling means, and adjustable means for supporting said hold-down barand for moving said hold-down bar toward and away from said sheetsupporting means.

4. Apparatus according to claim 1 characterized by an electric heatingelement for said heating means, and thermostat for maintaining saidheating means at a selected temperature.

1. Apparatus for making a mounting sheet for mounting a printing plateon a printing cylinder, said mounting sheet having astructurally-integral lip, said apparatus comprising means forsupporting a heat-softenable plastic sheet of a given size and shape andhaving at least one straight edge, an entry zone having means forreceiving and positioning the edge of the sheet, at least one heatingand forming zone having means for heating the edge of the sheet and forbending the edge upwardly away from the plane of the sheet andrearwardly in a direction substantially parallel to the plane of thesheet to form the structurallyintegral lip, and a cooling zone havingmeans for cooling the bent edge of the sheet while maintaining the bentedge in its bent position.
 2. Apparatus according to claim 1characterized by means for insulAting said heating means from saidcooling means.
 3. Apparatus according to claim 1 characterized by ahold-down bar extending substantially the length of said heating meansand said cooling means, and adjustable means for supporting saidhold-down bar and for moving said hold-down bar toward and away fromsaid sheet supporting means.
 4. Apparatus according to claim 1characterized by an electric heating element for said heating means, andthermostat for maintaining said heating means at a selected temperature.